<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        body{
            margin: 0;
            padding: 0;
            background: #333;
        }
        .midlle{
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%,-50%)
        }
        .bar{
            width: 6px;
            height: 60px;
            background: white;
            display: inline-block;
            transform-origin: bottom center;
            animation: loading 1.5s ease-in-out infinite;
        }
        .bar1{animation-delay: 0.1s;}
        .bar2{animation-delay: 0.2s;}
        .bar3{animation-delay: 0.3s;}
        .bar4{animation-delay: 0.4s;}
        .bar5{animation-delay: 0.5s;}
        .bar6{animation-delay: 0.6s;}
        .bar7{animation-delay: 0.7s;}
        .bar8{animation-delay: 0.8s;}
        @keyframes loading{
            0%{transform: scaleY(0.1);background: #fff;}
            50%{transform: scaleY(1);background: #2ecc71;}
            100%{transform: scaleY(0.1);background: transparent;}
        }
    </style>
</head>
<body>
    <div class="midlle">
        <div class="bar bar1"></div>
        <div class="bar bar2"></div>
        <div class="bar bar3"></div>
        <div class="bar bar4"></div>
        <div class="bar bar5"></div>
        <div class="bar bar6"></div>
        <div class="bar bar7"></div>
        <div class="bar bar8"></div>
    </div>
</body>
</html>